192 THE AMERICAN MIDLAND NATURALIST. 
allowed to grow along their sides, and by offering nesting 
sites they are probably of more value than harm to birds. 
The railways are all single track lines, with but few trainse 
daily. So far as:noticeable they have neither favorable nor 
unfavorable effect upon bird life. 
D.—INDUSTRIES, POPULATION. 
Floyd County is dominantly a region of grain farms. Corn 
is the principal grain raised, although there are large fields 
of oats. Pasture land is not extensive. 
Rockford, with a population of about 1,400 and Charles 
City, with a population of about 7,200 are the largest towns in 
the county. Charles City is dependent for much of its pres- 
perity upon the factory of the Hart-Parr Company, manu- 
facturers of oil tractors. There are other minor factories, 
and a very large nursery. The city is attractively built, with 
plenty of trees, large lawns, and a large wooded park, Wild- 
wood Park, to the southwest. 
Rockford, Nora Springs, Floyd, and Marble Rock are pe 
ing towns. There are several small villages, of no particular 
consequence to the fauna, in the country. 
Floyd County, therefore, is a typical section of the northern 
part of the Iowa corn belt. Its population is moderate, its 
industries mainly that of any farming community. Yet the 
effect of these industries and populations on animal life has 
been considerable. Generalizations on this subject would have 
little point; the specific examples are brought out in the 
various species noticed. 
I.—LIST OF SPECIES AND SUBSPECIES. 
1. Colymbus holboelli (Reinh.) Holboell’s Grebe. Webster 
states that this species nested near Charles City in the 60’s,- 
but it is now a very rare migrant. Webster reports a flock 
of six birds, seen near Hackberry Grove, Cerro Gordo county 
on March 26, 1916. I have a questionable record for May 
26, 1916, at Charles City. ° 
pee Columbus auritus (Linn.) Horned Grebe. Common 
migrant in “early days” (Webster). Now a rare migrant and 
rarer summer resident. Mr. J. H. Waddell reports a pair as. 
